The influence of aerobic exercise training on the double product break point in low-to-moderate risk adults

Abstract

The double product (DP) is the product of the heart rate (HR) and systolic blood pressure (SBP). The double product break point (DPBP) is a physiologic threshold that occurs at similar exercise intensities to that of the ventilatory threshold (VT). The influence of aerobic exercise training on the DPBP has not yet been examined. The purpose of this study was to examine whether aerobic exercise training (ET) increases the exercise intensity at which the DPBP occurs, and whether it increases in a similar fashion to the VT. Seven males and 11 females, all sedentary (mean ± SD: age = 29.9 ± 10.5 yr) underwent supervised cardiopulmonary exercise testing using a cycle ergometer ramp protocol at baseline and after eight weeks of vigorous ET on a cycle ergometer. The VT was determined by gas analysis and the V-slope method. Experienced observers using standardized instructions visually determined the DPBP. Following ET, VO 2peak , maximal workload, and body composition variables all showed significant positive changes. The VO 2 at which the DPBP and VT occurred increased significantly from baseline to follow-up (p <.001). At baseline and at follow-up, the DPBP and VT did not differ. The DPBP and VT were significantly correlated to each other at both time points. Results suggest that the DPBP responds to ET in a similar fashion to that of the VT, and may be an easier and more useful marker of the VT for exercise training purposes.

Respostas hemodinâmicas a um protocolo de treinamento isométrico de preensão manual

“…To eliminate any possibility of interference by the examiner on any differences or changes in hemodynamic variables, HR, SBP and DBP measurements were obtained using a digital Tango+ sphygmomanometer by the oscillometric method (Suntech, United States), using the detection of the RR interval of the electrocardiogram as reference, thus minimizing the influence of any noise or artifacts of the exercise, a basal value of 180 mmHg of inflation and a deflation rate of 5 This equipment is properly certified for blood pressure measurements, according to the technical standards of the country of manufacture, and has been used in other clinical studies [27][28][29] . Using the device's manual mode, measurements were made at rest, prior to determining the maximal handgrip strength, starting the inflation of the cuff at 20 and 80 seconds of the two maneuvers made with the left arm and also 1 minute after completion of the last maneuver.…”

Double product break point estimates ventilatory threshold in individuals with type 2 diabetes

“…Accordingly, there is a marked increase in sympathetic nerve activity, which results in a significant elevation of catecholamines, which is known as the catecholamines threshold 12 ) . The increased levels of catecholamines, in turn, result in a marked increase in BP and HR, and thus on DP, and as a result the DPBP 15 , 16 , 17 , 18 , 19 ) . Furthermore, increased levels of catecholamines also produce a significant increase in glycolytic activity 42 ) , enabling for the identification of the glycemic and lactate thresholds 3 ) .…”

“…The AT can be identified using several markers representing different physiological systems. For instance, the AT has been determined through the analysis of heart rate variability (HRV) 2 ) , blood catecholamines 12 ) , blood glucose and lactate 3 ) , ventilation and respiratory equivalents 13 , 14 ) , and the double product (DP) 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ) .…”

“…Identification of AT through different indices, such as the double product (DP), has been widely utilized for healthy individuals 16 , 17 , 19 ) , athletes 20 ) and individuals with cardiovascular diseases 15 , 16 , 18 ) . However, few studies have identified the AT of individuals with T2D through different methods 2 , 23 ) , while the exercise recommendations for T2D 24 ) indicate that these patients should be encouraged to undertake an exercise test before being submitted to physical training.…”

“…The validity of the DPBP in estimating the AT using a sphygmomanometer and stethoscope has not been investigated yet. Experiments have used either automated blood pressure monitor 15 , 16 , 17 , 19 , 20 , 23 ) or a cannula inserted into the brachial artery 18 ) . These procedures are not accessible to most practioners because they require costly equipment as well as highly invasive procedures.…”